Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f79eb900ae8058…

MALICIOUS

PDF

88.5 KB Created: 2021-06-28 10:21:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 4d355ec23ff99576c6fe1e41c635a0cc SHA-1: d7293ed41b139225761f66578b1f21162613fb38 SHA-256: 28f79eb900ae8058942763fd1905d2b49c7128ac864d3e95c134250ce3425f23
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple compromised domains and the structure of the PDF point towards an attempt to exploit users through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://escuelasfutbol8.com/docs/files/97309899301.pdf In PDF document text
    • https://service-panev.com/userfiles/94150122941.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/aeb7dbe76e914343208dc4ecfc4afecd/25937762875.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/8f340e3ceec3f13e7892bf811b7426ef/wigenutumaneruwokexafot.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160add0105310b---3672447989.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/340c7369a5609b4614462cce7baf514a/43706516756.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/8c2ef440aace0373c859f3b65d0df6bf/33569216168.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffea1721e1---pejemuxanazimep.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/56492753092.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/12593472872.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096452b23e7b---29996288025.pdfIn PDF document text
    • http://travelshops.pl/userfiles/file/nelekubap.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a05f103057c---41850343874.pdfIn PDF document text
    • http://k-souz.com/userfiles/file/sazimegilolon.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608110193512b---13060764092.pdfIn PDF document text
    • http://france-ex.com/images/blog//file/79604409121.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9331cbfa7---90713960820.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/0d66f4486c1160fa7a8889d4e019d73a/dokuwakumolonoroto.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab69a0055e3---bewadamelukumurodapa.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/6b9si8unuoo9k1kc52hm6v7q17/31512574741.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d401214ac4---91297216432.pdfIn PDF document text
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/23597898854.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/45792813069.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/nexijegivogaxiraredaliv.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/85298360420.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=long+division+sums+for+class+4PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF675 10792 bytes
SHA-256: 2ee7f7511adad3ef2ccb50d1443b518f8297641beae0bee08c6b3e7e0754d894
font_01_sfnt_off00010f26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12738 17472 bytes
SHA-256: fe59f209d44f337cf20bcb9daa68e76081c385dce6d95f2298454f4f4ff78078